horse-drawn rail car

[swaghauler]

Wheeled vehicles can cut their weight by a factor of 10... which is why you can push a passenger car weighing 3k pounds by yourself.

[Vespers War]

The general rules of thumb I've run across for hauling by horses for actual work and not tractor-pull style demonstrations:

1/10 of body weight in dead weight (like a plow or log)
1.5x body weight on wheels on road
5x body weight on rails

So a 75 ton loaded rail car will need at least 15 tons of horse to pull. Figure around 10 draft horses or so.

That's also assuming level track and a relatively low speed (circa 8km/h or 5mph). Hills will need a "booster" team to help haul, and teams will probably need to be swapped every 3-4 hours (let's say 4 just to make it equal to a travel period).

[ChalkLine]

Generally a draisine horse-drawn vehicle was very lightweight, you'd probably need a specialist car. This is good as you can make one up yourself. It would have two axles and probably a canvas bows cover taken from trucks. You'd simply pull more of them if you needed more capacity.

If you need a standard car you can use an alcohol engine dragging one car. Remember it needs a big pneumatic system to slow the car

[CraigD6er]

An interesting idea and I wonder why we don’t see more use of rail lines like this. I seem to recall Stirling mentioned using horse or ox drawn wagons on rails in the first 2 or 3 of his Emberverse series, before it went too fantasy for my liking. I think he even mentioned sped/capacity at some point. Oxen would pull more for longer I think, but would be rarer.

The weight sounds about right for the carriage; it varies depending on what the carriage is fitted for, whether it has its own motors, toilet etc, but 50t is a good average. If the carriage is pretty much being used as a one-time ambulance, then leave it as is. If however it is a conversion that was/is/will be used regularly, then you can shave some of the weight from the 50t. A half decent engineering team might be assigned the role of moding some carriages to serve in the new conditions.
There are a lot of things that are unnecessary in this environment. Based on a little knowledge of UK rolling stock I would suggest it be stripped to bare bones; remember this is Warpac and comfort was never likely to be a major concern anyway, let alone now. Ditch anything that is unnecessary.
Much of the function of train systems relies on connection to the power car and there is little independence in each carriage. There are a lot of pipes and cables that run the length of a train that won’t be needed anymore.
Remove most/all seats. Lightweight rig to hold litters, and any seats left don't need to be heavy enough to withstand the stress of high speed or crashes. Bolt in the lightest ones salvaged from a ruined factory mess room.
Remove the toilet possibly, CET tank definitely! A CET tank is Controlled Emissions Tank and holds whatever goes into the toilet until it can be emptied at depot. It is often to be found slung under a carriage, on the underframe. I doubt anyone will be worrying about effluent going on the tracks when weight can be saved or when horses and oxen are adding their own anyway (side image, locals rushing out when a horse drawn carriage or two goes by to collect the fertilizer!).
Remove anything to do with lighting, heating, p.a. systems. All rely on the power car to work. Lots of pipework and cable runs through a carriage for these. Generators and transformers are slung under the carriage and could be ditched too unless you can power them (generally they are either linked to the power car or use a dynamo system off the bogie axles, but I doubt they’d work at horse drawn speeds). Standby batteries underneath are heavy and useless unless they can be charged.
Much of the underframe equipment for brakes could be ditched; large air tanks, pipework (probably metal), heavy duty callipers and brake shoes. Remember these are designed for stopping not just the 1 carriage but to aid stopping the whole train weighing several hundred tons running at speed. Again, they need control and power from the engine or power car. Carriages have a default, if connections fail then the emergency brakes come on automatically. That would need to be overruled or the horses will be trying to shift the carriage with brakes locked on. Replace with something simpler, such as a simple pneumatic system to cope with any inclines.
Couplings between carriages can go as you're probably running each carriage singularly.
Any weight saving makes the horses job easier and allows you more wriggle room when you work out your speeds. Unless you have a rolling stock engineer in your group, no one’s going to quibble if you say that's a 3t or a 10t saving.

[Adm.Lee]

The good news is that the PCs aren't likely to use this, so I don't need to worry about them looking too closely.

Stripping out the air-conditioning and heaters, I hadn't thought of that, that's a good bit of weight savings. The air brake equipment can go, I was going to leave in the handbrakes, so the car can be held in place and stopped when needed.

I am thinking this is not a one-time trip, so sleeping arrangements will likely stay. It's not expected to be a high-speed service, just stable and not tie up other transport assets. I am assuming pretty level track, but I know that's never truly level.

10-15 horses sounds like a lot, maybe not saving much in the way of power vs a handful of wagons, and would be more likely to draw a bigger escort than I need for game purposes. Maybe I will drop back to a single alcohol-fueled truck-- rigged for rail-running-- towing the car.
* If I do that, I can leave an axle-driven generator and batteries for lighting.
* If I do that, maybe there's actually an operating room at one end of the car? Nah, that will be a different car, hauled into place nearer the front and left there, while this car is used to shuttle back to a base area.

Plan B would be to take one or more actual ambulances, cut off the cabs and engines, reset the wheels for rail travel, and tow a string of 2-3 of those behind a few horses.

[swaghauler]

I don't doubt for a second that you could roll such a car with a team of 8 Clydesdales. The Budweiser team routinely pulls 50 tons of rolling weight at a trot without injury. A single Amish Courser will pull a wagon and up to 6 human passengers at a trot without injury (an estimated weight of 2 metric tons with passengers).
Oxen would be the better choice as they do better in rough terrain (do to having a cloven hoof) and can easily drag 3 times their own weight. An ox team of 4 can pull what 8 Clydesdales can pull. Thus, an 8 ox team could easily pull 100 tons of rolling weight. The ox do move slower than horses, however. You will get about 80% of the range of a horse team.

[chico20854]

Another thing to keep in mind is the return trip. The Soviets aren't too likely to devote that level of resources to an asset that will only be used half the time. (Doctrinally, Soviet wounded would be evacuated on empty ammunition trucks returning from the front). So to the extent that it didn't impair the primary mission adding features so it could be used for troop transport or cargo carriage on the return trip would be a useful bonus!

[Vespers War]

Originally Posted by swaghauler

I don't doubt for a second that you could roll such a car with a team of 8 Clydesdales. The Budweiser team routinely pulls 50 tons of rolling weight at a trot without injury. A single Amish Courser will pull a wagon and up to 6 human passengers at a trot without injury (an estimated weight of 2 metric tons with passengers).
Oxen would be the better choice as they do better in rough terrain (do to having a cloven hoof) and can easily drag 3 times their own weight. An ox team of 4 can pull what 8 Clydesdales can pull. Thus, an 8 ox team could easily pull 100 tons of rolling weight. The ox do move slower than horses, however. You will get about 80% of the range of a horse team.

An enclosed Amish buggy is about half a ton (a buckboard is under 450 pounds), so either those passengers average 500+ pounds each or the weight estimate seems a bit high; the total weight might be under a tonne if there are children or small adults among the six passengers. Charleston, SC has horse-drawn carriages that weigh 1800 pounds empty and carry 16 passengers while staying under 5000 pounds (2.27 tonnes) total draw weight.

Somewhat contradicting my earlier position, Robert Stevenson was of the opinion that a single horse on well-constructed rail on the level could draw ten tons, but that was during a time when the longevity of the horse was not a concern and they'd be worn out within a couple of years. I suspect the rules of thumb I learned were intended to keep the horses' health as a prime concern and load them more lightly than their maximum for that reason.